Complex social communication via language is a central aspect of human interactions. A key neural process underlying language is vocal learning, the ability to learn the particular sound combinations that compose a language. While most people learn their primary language(s) as children, learning of a new language as an adult does occur, particularly by foreign-born immigrants but also by recipients of cochlear implants and by stroke victims. Yet little is known about how the adult brain learns languages. Mutations in the transcription factor FoxP2 are known to be responsible for speech defects in humans. Work in the zebra finch, a songbird models for vocal learning, has suggested that the transcription factor FoxP2 plays an important role during the juvenile phase in regulating other genes that structure the neural centers for vocal learning and enhance the neural connections required for learning. Importantly, the zebra finch is capable of learning only as a juvenile, limiting its effectiveness as a model for adult vocal learning. In this SC1 project we will employ an alternative model, the budgerigar (a small parrot) that commonly learns new calls as an adult. We will use this model to investigate of the role of FoxP2 in adult vocal learning. We will use a viral vector developed for gene therapy to increase the gene expression of FoxP2 in a particular vocal learning center of budgerigars. We will then examine the resulting effects on vocal plasticity, social behavior, neuron shape and networks of gene expression. We predict that elevated FoxP2 activity will inhibit vocal plasticity and reduce or block completely the abiliy of treated birds to learn new vocalizations. Students and a postdoctoral trainee from a minority-serving institution will be involved in all aspects of the research and will receive training in cutting-edge techniques in neuroscience from a suite of highly-experienced collaborators.